On Monday, 18 December 2017 03:57:01 UTC, wrote:
On Sunday, 17 December 2017 22:38:05 UTC, Phil Addison wrote:
My old fluorescent under-kitchen-cabinet tubes are failing at an ever faster rate, so I'm
thinking of replacing with LEDs, particularly flexible LED tapes.

A few things I'm not sure about...

The light output is quoted in lumens per metre, but how many do I need?

How long is a piece of string. What do your current lights put out, estimate from there.

See previous reply

or does it need to be
mounted into a holder such as RS Stock No. 797-2432, a horrendously expensive product!

there's never any reason to buy anything from RS.

I certainly wasn't suggesting I'd buy them from RS, just pointing out an example.

Then there's colour temperature. My fluorescents are 2700K but a lot of the white LEDs
seem to be 3000+. I don't suppose that's a big deal in this application.

3000K is not as yellowy tinged as 2700K. I'd avoid higher CCTs unless you know you want them.

ok

What about drivers. I assume I'll just need a couple of basic 12V drivers, one each side
of the sink - though the hob interrupts the run on the right, so I'll either have to route
some cable round that of use a 3rd driver for the last cabinet which will only has a 55cm
LED run. I have easy access to the 240VAC that's feeding the 6 existing tubes. Something
like a couple of RS number 773-6949 drivers giving 1 amp each?

12v 1A is 12watts.

No **** Sherlock

I'd give them at least one dimmed setting. For relaxed use it looks better and extends LED life hugely. A series cap on the mains feed can do that, as long as the PSUs don't misbehave.

Its only under cabinet lighting. There is an on-off wall-switch for when they are not wanted.